Shrink wrapped package

ABSTRACT

A package composed of a single rectangular sheet of corrugated pasteboard providing a pair of juxtaposed compartments, the package construction includes a bottom wall, upstanding end walls and a top wall, the top wall being defined by the free ends of the pasteboard sheet disposed in overlapping relation over said brace; at least one integral upright brace formed by folding sections of the bottom wall; means for securing sections of the brace to each other; and a heat-shrunk, transparent, thermoplastic film enveloping the package.

United States Patent [72] Inventor John Paul Cooper -Wilton, Conn. [21]Appl. No. 886,428 [22] Filed Dec. 18, 1969 [45] Patented Dec. 14, 1971[73] Assignee Borden Inc.

New York, N.Y.

[54] SHRINK WRAPPED PACKAGE 4 Claims, 4 Drawing Figs.

[52] US. Cl 206/45.33, 206/65 S, 229/27, 229/DlG. l2 [5 l] Int. Cl 865d65/16 [50] Field of Search 206/4533, 65 S, 65 R, 46 PR, 80 A; 229/] S,27, 37 R, 42, DIG. 12

[56] References Cited UNITED STATES PATENTS 2.491.206 12/1949 Potts229/15 X 2,979,191 4/1961 Kyassay et al. l. 206/4533 3,493,106 2/1970Galli 206/65 S 3,493,107 2/1970 Markey 206/65 S Primary Examiner-JosephR. Leclair Assistant ExaminerSteven E. Lipman Attorneys-George P. Maskasand George A. Kap

ABSTRACT: A package composed of a single rectangular sheet of corrugatedpasteboard providing a pair of juxtaposed compartments, the packageconstruction includes a bottom wall, upstanding end walls and a topwall, the top wall being defined by the free ends of the pasteboardsheet disposed in overlapping relation over said brace; at least oneintegral upright brace formed by folding sections of the bottom wall;means for securing sections of the brace to each other; and aheat-shrunk, transparent, thermoplastic film enveloping the packagev WWWmm 14, 1971 BMWAW 26 INVENTOR mam mm. wmwm BY 2* ATTORNEY snruNK WRAPPEDPACKAGE BACKGROUND OF THE INVENTION Heretofore, packages for encasingcontainers of foodstuffs and other products have conventionally beenopen-topped comprising integral sidewalls with foldable flaps on theedges; the fiaps are assembled to define top and bottom walls to enclosethe contents. Usually, the bottom wall is first assembled and thecartons are positioned in rows in the package; thereafter, the top flapsare assembled to establish the top wall and the filled packages arestacked and transported for use. Dividers are often inserted into thepackage to separate the stored contents.

To date, virtually no imagination has been exercised in the constructionof such packages; lack of selfand semisupporting product packagesfrequently causes the outer package wall to warp and eventually buckle.In addition, most corrugated boxes lack sufficient columnar strength tobuild high stacks, i.e., the compressive stresses of stacking cause thepackage walls to collapse with resultant destruction of the contents.

Another disadvantage of known packages is the difficulty of assembly.The flaps of the top and bottom wall often include mating portions whichare difficult to align, and once aligned, require the addition of anadhesive or staples to maintain the assembly. Besides lacking strengthand being difficult to assemble, most packages lack aesthetic appeal.Finally, the conventional, fully enclosed package provides no visualaccess to the interior to view the condition of the contents.

SUMMARY OF THE INVENTION The present invention overcomes the stateddeficiencies of the prior art and has as its primary objective a packageconstruction which is simple to assemble, possesses high columnarstrength to withstand the forces of loading and stacking and permitsinspection of the contents.

The package of the present invention comprises dual compartments, eachdimensioned to the size of the encased articles thus assuring a snug fitto take advantage of all support available. This constructionestablishes a central, integral brace which eliminates the need forinserts or spacers. Though an empty package possesses sufficientstrength to withstand normal loads, the filled package draws additionalstrength from the stored carton walls to preserve the integrity of thesidewalls against stacking loads.

The package is enrobed in a transparent thermoplastic film and subjectedto a heated environment to heat shrink the film and thus define a neat,tightly drawn, film-enrobed package.

The package is formed from a single sheet of corrugated or fiberboard orthe like. With corrugated sheet, the fluting of the sandwich layer ofthe sheet is parallel to the longitudinal axis: the sheet is foldedalong transverse score lines to define the walls of the package.

BRIEF DESCRIPTION OF THE DRAWING The various features of the apparatusof this invention will become apparent from the following detaileddescription set forth in connection with the accompanying drawing whichrelates to the preferred embodiment of the present invention and isgiven by way of illustration.

FIG. I is an isometric perspective view of the preferred embodiment ofthe assembled package enrobed in a heatshrunk film;

FIG. 2 is a perspective view of an unfolded sheet prior to assembly ofthe package, partially broken away to illustrate the fluting;

FIG. 3 is a perspective view of the invention partially assembled;

FIG. 4 is a cross section view taken along the line IV-IV of FIG. I.

DETAILED DESCRIPTION OF THE INVENTION Referring to the preferredembodiment of the present invention, an assembled package 10 comprisesan integral pasteboard sheet ll folded to define juxtaposed compartmentsA and B and enrobed in a tightly drawn transparent plastic film.

Focusing first on member 11, shown unfolded in FIG. 2, a rectangularsheet of corrugated pasteboard or the like is used. Sheet llll comprisesdimensionally equal layers 13 and 14 of pulp or the like between whichis sandwiched a folded sheet of heavy grade paper I5 of ogee crosssection to define longitudinally extending flutes. The flutes must beparallel to the length to reinforce the package sidewalls againstcompressive loading forces when the latter are disposed in the uprightposition ofFIG. I.

A central score line 16 and parallel, equally spaced score lines 17 and18 are provided on sheet 11 transversely to the longitudinal axis.Additional parallel, transverse score line pairs, 20, Eli and 22, 23 aredisposed on opposite sides of the central score line I6. The spacingbetween score lines 18 and 2t) equals the distance between lines 17 and22; the dimension between 20 and 21 equals that between lines 22 and 23.

In assembly, shown in FIG. 3, the sheet 11 is bent along the score linesto form an interface between the surfaces bounded by lines 17 and H8.The surface between lines 20 and 21 defines one sidewall 25 disposed,preferably, at right angles to bottom wall 26 between lines 18 and 20.In a like manner, a sidewall 27 is defined between lines 22 and 23,positioned at right angles to bottom wall 28. The interface 19 definedbetween the juxtaposed sections between score lines 17 and I8 isprovided with an adhesive or other suitable securing means to establisha centrally positioned unitized interior brace 30.

The sections from lines ZI and 23 bounded by the free edges of the sheetare reentrantly folded and overlapped to define the top wall 3B of theopen-ended package, seen in FIG. 4%. In practice, the strongest packageis produced by situating a portion of the overlapped section 32 tosurmount the upstanding brace 30. Suitable retaining means may be used,such as adhesive or staples, to secure the interface established by theoverlapped ends.

The cartons, containing the commodity to be packaged, are inserted in anopen compartment position of the package. The score line spacing isbased on the dimensions of the product to be packaged and may be uniformor nonuniform to accommodate the cartons. Preferably, rows of productare packed in each compartment. By making scoreliine spacing a functionof the carton dimensions, the compartments are fully occupied by thepackage rows. This reduces the relative movement between cartons in eachcompartment, package material wasteage and production costs, and wallbuckling, since snug fitting product packages impart interiordimensional stability. By this construction, optimal columnar strengthis realized.

Once parallel rows of cartons are deposited in the assembled package,the combination is enrobed in a plastic film or wrap, such as paper. Anywrap will suffice, especially if it pos sesses shrinkable properties. Inpractice, polyvinylchloride or polyethylene has rendered the bestresults though this disclosure should not be so limited. By subjectingthe thermoplastic enrobed package to a heat environment, the filmshrinks to clearly define the walls of folded sheet I1 and additionallyserves to retain the assembled position by resisting outward flexing ofthe walls. The package may be completely sealed in the plastic envelopeto preclude the entry of water, dirt, and foreign matter and permitvisual access to the contents through the transparent film.

The strongest packages have been produced by selecting the number ofrows and layers of product packages to be arranged in the compartmentsso that the following ratios of compartment dimensions based onscoreline spacing may be achieved: height/width from about 0.33 to about0.625; and depth/width from about 0.! to about 0.025. Generally, loadingstresses are related to board strength and product package support. Inparticular, the positioning of the fluting in the pasteboard to resistthe downward compressive stresses of loading has contributed to boxstrength. It should further be appreciated that a plurality of integral,internal braces may be provided to divide the assembled package intoseveral compartments. This is accomplished by providing additional scorelines. In practice, greatest columnar strength is achieved by multiplebraces providing multiple cavity packages.

What is claimed is:

1. A package made from a single sheet of material and having at least apair of juxtaposed compartments adapted to receive a plurality ofcontainers disposed in snug rows to fully occupy said compartmentscomprising:

a. a rectangular sheet;

b. said sheet being folded to define a bottom wall, upstanding sidewallsand a top wall;

c. said bottom wall including at least one integral upstanding braceestablished by juxtaposed folded sections of said bottom wall disposedparallel to said sidewalls and being dimensionally coextensivetherewith, said brace separating said compartments;

d. said top wall defined by the free ends of said sheet disposed inoverlapping relation, at least a portion of said overlap surmounting thetop edge of said brace; and

e. means for securing the interface of said juxtaposed folded sectionsto each other.

2. Package of claim 1 wherein said rectangular sheet is corrugatedpasteboard having an integral, flute-folded inner layer whose flutes areparallel to the longitudinal dimension of said sheet.

3. Package of claim 2 including a heat-shrunk, transparent,thermoplastic film enrobing said sheet whereby a stable, compact packageis formed to permit visual access to the stored contents.

4. Package of claim 3 including means for maintaining said overlappedfree ends of said top wall surmounting the top edge of said brace.

I F i i i

1. A package made from a single sheet of material and having at least apair of juxtaposed compartments adapted to receive a plurality ofcontainers disposed in snug rows to fully occupy said compartmentscomprising: a. a rectangular sheet; b. said sheet being folded to definea bottom wall, upstanding sidewalls and a top wall; c. said bottom wallincluding at least one integral upstanding brace established byjuxtaposed folded sections of said bottom wall disposed parallel to saidsidewalls and being dimensionally coextensive therewith, said braceseparating said compartments; d. said top wall defined by the free endsof said sheet disposed in overlapping relation, at least a portion ofsaid overlap surmounting the top edge of said brace; and e. means forsecuring the interface of said juxtaposed folded sections to each other.2. Package of claim 1 wherein said rectangular sheet is corrugatedpasteboard having an integral, flute-folded inner layer whose flutes areparallel to the longitudinal dimension of said sheet.
 3. Package ofclaim 2 including a heat-shrunk, transparent, thermoplastic filmenrobing said sheet whereby a stable, compact package is formed topermit visual access to the stored contents.
 4. Package of claim 3including means for maintaining said overlapped free ends of said topwall surmounting the top edge of said brace.